For people interested in a possibly, maybe, potentially correct regular expression to parse email addresses: Here's the code of some perl module that afaik is correct (but then I'd have no idea how to validate it, so I'm just repeating what other, hopefully more educated people have claimed):

As @Bohemian says, the regular expression for checking an e-mail address is not what you give, and is so complicated that it is better to conclude that a regular-expression is not the right approach.
–
RaedwaldNov 4 '11 at 13:35